linux-kernel - [PATCH] PCI/MSI: Size device MSI domain with the maximum number of vectors

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250603141801.915305-1-maz@kernel.org>
Date: Tue,  3 Jun 2025 15:18:01 +0100
From: Marc Zyngier <maz@...nel.org>
To: linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org
Cc: Thomas Gleixner <tglx@...utronix.de>,
	Lorenzo Pieralisi <lpieralisi@...nel.org>,
	Zenghui Yu <yuzenghui@...wei.com>
Subject: [PATCH] PCI/MSI: Size device MSI domain with the maximum number of vectors

Zenghui reports that since 1396e89e09f0 ("genirq/msi: Move prepare()
call to per-device allocation"), his Multi-MSI capable device isn't
working anymore.

This is a consequence of 15c72f824b32 ("PCI/MSI: Add support for
per device MSI[X] domains"), which always creates a MSI domain of
size 1, even in the presence of Multi-MSI.

While this was somehow working until then, moving the .prepare()
call ends up sizing the ITS table with a tiny value for this device,
and making the endpoint driver unhappy.

Instead, always create the domain (and call the .prepare() helper)
with the maximum expected size.

Fixes: 1396e89e09f0 ("genirq/msi: Move prepare() call to per-device allocation")
Fixes: 15c72f824b32 ("PCI/MSI: Add support for per device MSI[X] domains")
Link: https://lore.kernel.org/r/0b1d7aec-1eac-a9cd-502a-339e216e08a1@huawei.com
Reported-by: Zenghui Yu <yuzenghui@...wei.com>
Tested-by: Zenghui Yu <yuzenghui@...wei.com>
Signed-off-by: Marc Zyngier <maz@...nel.org>
---
 drivers/pci/msi/irqdomain.c | 5 +++--
 drivers/pci/msi/msi.c       | 8 ++++----
 drivers/pci/msi/msi.h       | 2 +-
 3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
index d7ba8795d60f..c05152733993 100644
--- a/drivers/pci/msi/irqdomain.c
+++ b/drivers/pci/msi/irqdomain.c
@@ -271,6 +271,7 @@ static bool pci_create_device_domain(struct pci_dev *pdev, const struct msi_doma
 /**
  * pci_setup_msi_device_domain - Setup a device MSI interrupt domain
  * @pdev:	The PCI device to create the domain on
+ * @hwsize:	The maximum number of MSI vectors
  *
  * Return:
  *  True when:
@@ -287,7 +288,7 @@ static bool pci_create_device_domain(struct pci_dev *pdev, const struct msi_doma
  *	- The device is removed
  *	- MSI is disabled and a MSI-X domain is created
  */
-bool pci_setup_msi_device_domain(struct pci_dev *pdev)
+bool pci_setup_msi_device_domain(struct pci_dev *pdev, unsigned int hwsize)
 {
 	if (WARN_ON_ONCE(pdev->msix_enabled))
 		return false;
@@ -297,7 +298,7 @@ bool pci_setup_msi_device_domain(struct pci_dev *pdev)
 	if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSIX))
 		msi_remove_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN);
 
-	return pci_create_device_domain(pdev, &pci_msi_template, 1);
+	return pci_create_device_domain(pdev, &pci_msi_template, hwsize);
 }
 
 /**
diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index d6ce04054702..6ede55a7c5e6 100644
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -439,16 +439,16 @@ int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
 	if (nvec < minvec)
 		return -ENOSPC;
 
-	if (nvec > maxvec)
-		nvec = maxvec;
-
 	rc = pci_setup_msi_context(dev);
 	if (rc)
 		return rc;
 
-	if (!pci_setup_msi_device_domain(dev))
+	if (!pci_setup_msi_device_domain(dev, nvec))
 		return -ENODEV;
 
+	if (nvec > maxvec)
+		nvec = maxvec;
+
 	for (;;) {
 		if (affd) {
 			nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
diff --git a/drivers/pci/msi/msi.h b/drivers/pci/msi/msi.h
index fc70b601e942..0b420b319f50 100644
--- a/drivers/pci/msi/msi.h
+++ b/drivers/pci/msi/msi.h
@@ -107,7 +107,7 @@ enum support_mode {
 };
 
 bool pci_msi_domain_supports(struct pci_dev *dev, unsigned int feature_mask, enum support_mode mode);
-bool pci_setup_msi_device_domain(struct pci_dev *pdev);
+bool pci_setup_msi_device_domain(struct pci_dev *pdev, unsigned int hwsize);
 bool pci_setup_msix_device_domain(struct pci_dev *pdev, unsigned int hwsize);
 
 /* Legacy (!IRQDOMAIN) fallbacks */
-- 
2.47.2